跳至主要内容

How should we select defoamers / antifoams for paper pulp?

How should we select defoamers / antifoams for paper pulp?defoamers for paper pulp

Pulp and paper antifoaming agents is very necessary in papermaking, because a lot of foam will be generated in the process of papermaking and pulping, the surface tension of the generated saponification is less than the surface tension of black liquor produced by cooking materials, making it It exists in the surface layer of black liquor and forms a thin film, which forms foam under the mixing action of air.

The papermaking process is mainly divided into two major steps,

  •  Washing pulp
  • Papermaking

No matter which step inevitably produces foam, so you need to use defoamers/antifoam for paper industry, there are many types of defoamers, the following is for everyone Introduce the characteristics of papermaking defoamers.

Excessive foaming will result in the loss of fibers and raw materials. Further, the presence of air in the wet paper web can affect the filtration rate of paper in the paper making pulp defoamers is a better solution to foam.

In the pulping process, because the slurry contains natural substances such as fatty acids and resin acids, fatty acids soap, fatty acid soap and other foaming substances will be generated after cooking liquid and chemical washing.

 

A large amount of foam will bring certain cleaning and conveying and bleaching. The trouble caused by the pulp quality decline, so the need to use defoamers for processing. The defoamers used in the pulping process mainly include hydrocarbon defoamers and silicone emulsion defoamers. This type of defoamer can quickly eliminate the foam generated by lignin and some surfactants, and the use effect is particularly obvious when the pulp is washed.

For the papermaking process, if the bubbles generated in the papermaking process are not resolved, it will cause paper breaks, white water level fluctuations, pump frequency fluctuations, etc., which directly affect the stability and quality of paper production. The papermaking defoamer can effectively suppress the white water foaming, and at the same time, for the fine bubbles entrained between the fibers, the foam on the surface of the slurry can be eliminated. The defoamer can also dissolve the air in the pulp and eliminate the large bubbles on the water surface. In this way, the formation of holes can be avoided, and the overflow of the paper break and the storage tank can be reduced, thereby ensuring the loss of pulp fibers and chemicals, making The uniformity and quality of the paper have been improved.

1. Defoamers/antifoams for papermaking and paper pulp:

mainly used to control alkaline pulping, papermaking washing, bamboo pulp, sugarcane pulp, neutral pulping, paper pulp, pulp rinsing, screening, bleaching, water treatment, plant fiber pulp production In the foam. Has the following characteristics:

  • Strong defoaming and foam breaking properties;
  • Quickly and thoroughly improve filter drainage;
  • Good mutual solubility in black liquor, suitable for the production conditions of the pulp mill;
  • Can improve the rinsing efficiency;
  • Reduce salt loss and improve pulp quality;
  • Reduce the content of bleaching chemicals to meet environmental protection requirements;
  • The raw material is biodegradable, non-toxic and harmless.

2. Defoamers/antifoams for papermaking:

Defoamers for papermaking and papermaking are used in papermaking white water; surface foam containing rosin gum, bubbles adsorbed on fibers in water, surface foam containing modified starch white water system, water foam containing polyacrylamide retention aid system, and The surface foam containing AKD emulsion white water system is eliminated. The main features are:

  • Fast defoaming speed and long foam suppression time;
  • Good dispersion, dynamic defoaming, no silicon;
  • Good product stability.

https://www.linkedin.com/company/china-defoamer

https://invelydefoamer.blogspot.com/

https://www.facebook.com/invelychem/

标签：

评论

发表评论

此博客中的热门博文

Defoamer for Beet Sugar Production: Effective Solutions to Foam Challenges

oam is a major problem in beet sugar production, especially during diffusion and purification stages. In our latest article, we explore the best defoamer solutions for beet sugar production , including real case studies and product recommendations for high-temperature and high-protein systems. 👉 Read Full Article
发表评论
阅读全文

invely-defoamers

Why Foam could be so inconvenient ? A light foam is generally not problematic in most applications however heavy foaming can often lead to various processing problems. These problems range from inaccurate readings from control and measuring equipment such as temperature, level and density controllers to poor mixing of reactants in chemical reaction vessels and products hanging in the foam, all too often leading to losses in production. Finally the presence of foaming can give a bad image of the way a process is operated in the eyes of a customer. The presence of foam in discharged effluent can cause complaints from local people and authorities even if the foam is harmless to people and the environment. How do silicone defoamers work ? Foam is a gas dispersion in a liquid or solid continuous phase. Foam iscreated by the surfactants which are at the air/liquid interface. Therefore air bubbles occur and are stabilised by the surfactants. Today, silicone antifoams are thebest solution to a...
发表评论
阅读全文

How do we assess antifoam efficiency ?

How do we assess antifoam efficiency ? Quality of an antifoam is given by two main characteristics : • Knockdown ability or shock effect :Meaning the speed to destroy an existing foam. • Persistence or durability : Meaning the efficiency over time.   These two parameters can be assessed by several tests. The main test is the bubbling method. A graduated column with a glass frit in the bottom is required. Foaming water is poured in the column and air at constant flowrate is introduced through the glass frit in the column. Foam is generated by the air and starts to travel up the column. At a determined level of foam, antifoam is injected. By this method several antifoaming agents can be tested. A graph reporting foam height vs time is very helpful to establish the knockdown ability and the persistence for each product. The selected antifoam is the product with the best compromise between shock effect and durability       Environmental performance   Silicone antifo...
1 条评论
阅读全文